PMID- 9156180
OWN - NLM
STAT- MEDLINE
DCOM- 19970623
LR  - 20190728
IS  - 0042-6989 (Print)
IS  - 0042-6989 (Linking)
VI  - 37
IP  - 7
DP  - 1997 Apr
TI  - Characterization of glutamate transporter function in the tiger salamander 
      retina.
PG  - 827-38
AB  - Glutamate transporters in the tiger salamander retina were studied by 
      autoradiographic and intracellular recording techniques. When the retina was 
      incubated with 15 microM L-[3H]glutamate, photoreceptors and Muller cells were 
      labeled, indicating that these cells had high-affinity glutamate uptake 
      transporters. A much higher dose of glutamate than kainate was required in the 
      bath to produce the same membrane depolarization in horizontal cells (HCs), and 
      the time course of glutamate-induced depolarization was much slower than that of 
      the kainate-induced depolarization. Since glutamate is a substrate of glutamate 
      transporters whereas kainate is not, we attribute these differences to the 
      buffering of extracellular glutamate by glutamate transporters in the retina. 
      D-aspartate (D-asp) increased the efficacy of bath-applied glutamate. 
      Dihydrokainate (DHKA) exerted little effect on glutamate efficacy when applied 
      alone, but it increased glutamate efficacy in the presence of D-asp. These 
      results are consistent with the notion that glutamate transporters in Muller 
      cells are D-asp sensitive and those in photoreceptors are DHKA and D-asp 
      sensitive. Application of DHKA (1-2 mM) did not affect the dark membrane 
      potential or the light responses in rods and cones, but it depolarized the HC 
      dark membrane potential and reduced the HC peak and tail light responses. Our 
      results suggest that DHKA-sensitive glutamate transporters in photoreceptors 
      regulate glutamate levels in rod and cone synaptic clefts. They modulate dark 
      membrane potential and the relative rod cone inputs in retinal HCs.
FAU - Yang, J H
AU  - Yang JH
AD  - Cullen Eye Institute, Houston, TX, USA.
FAU - Wu, S M
AU  - Wu SM
LA  - eng
GR  - EY04446/EY/NEI NIH HHS/United States
PT  - Journal Article
PT  - Research Support, Non-U.S. Gov't
PT  - Research Support, U.S. Gov't, P.H.S.
PL  - England
TA  - Vision Res
JT  - Vision research
JID - 0417402
RN  - 0 (ATP-Binding Cassette Transporters)
RN  - 0 (Amino Acid Transport System X-AG)
RN  - 0 (Glutamates)
RN  - 30KYC7MIAI (Aspartic Acid)
RN  - 52497-36-6 (dihydrokainic acid)
RN  - SIV03811UC (Kainic Acid)
SB  - IM
MH  - ATP-Binding Cassette Transporters/metabolism
MH  - Ambystoma
MH  - Amino Acid Transport System X-AG
MH  - Animals
MH  - Aspartic Acid/pharmacology
MH  - Autoradiography
MH  - Biological Transport/drug effects
MH  - Glutamates/*metabolism
MH  - In Vitro Techniques
MH  - Kainic Acid/analogs & derivatives/pharmacology
MH  - Membrane Potentials
MH  - Microscopy, Electron
MH  - Photic Stimulation
MH  - Retina/*metabolism/ultrastructure
MH  - Time Factors
EDAT- 1997/04/01 00:00
MHDA- 1997/04/01 00:01
CRDT- 1997/04/01 00:00
PHST- 1997/04/01 00:00 [pubmed]
PHST- 1997/04/01 00:01 [medline]
PHST- 1997/04/01 00:00 [entrez]
AID - S0042698996002313 [pii]
AID - 10.1016/s0042-6989(96)00231-3 [doi]
PST - ppublish
SO  - Vision Res. 1997 Apr;37(7):827-38. doi: 10.1016/s0042-6989(96)00231-3.